<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>当然是分开的p1存了就只有p1有</title>
	</head>
	<body>
		<script>
			class Point {
			    constructor() { }
			}
			let p1 = new Point();
			p1.username = 'zhangsan';
			console.log(p1.username);   //zhangsan
			
			let p2 = new Point();
			console.log(p2.username);   //undefined
		</script>
	</body>
</html>
